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#include "handler.h"
#include <termios.h>
#include <sys/ioctl.h>
namespace ov4
{
sigset_t
block_sig_TTOU,
block_job,
block_io;
void signal_init()
{
/* Install the signal handlers */
sigemptyset(&block_job);
sigemptyset(&block_sig_TTOU);
sigemptyset(&block_io);
sigaddset(&block_job, SIGINT);
sigaddset(&block_job, SIGTSTP);
sigaddset(&block_job, SIGCHLD);
sigaddset(&block_sig_TTOU, SIGTTOU);
sigaddset(&block_io, SIGTTOU);
sigaddset(&block_io, SIGTTIN);
Signal(SIGINT, sigint_handler); /* ctrl-c */
Signal(SIGTSTP, sigtstp_handler); /* ctrl-z */
Signal(SIGCHLD, sigchld_handler); /* Terminated or stopped child */
}
/*
* Signal - wrapper for the sigaction function
*/
handler_t *Signal([[maybe_unused]] int signum, handler_t *handler)
{
struct sigaction action, old_action;
action.sa_handler = handler;
sigemptyset(&action.sa_mask); /* block sigs of type being handled */
action.sa_flags = SA_RESTART; /* restart syscalls if possible */
if (sigaction(signum, &action, &old_action) < 0)
unix_error("Signal error");
return (old_action.sa_handler);
}
/*
* sigchld_handler - The kernel sends a SIGCHLD to the shell whenever
* a child job terminates (becomes a zombie), or stops because it
* received a SIGSTOP or SIGTSTP signal. The handler reaps all
* available zombie children, but doesn't wait for any other
* currently running children to terminate.
*/
void sigchld_handler([[maybe_unused]] int sig)
{
int errno_backup = errno;
sigset_t prev;
block_handler(&prev);
int status, pid;
safe_debug("SIGCHLD\n");
while ((pid = waitpid(-1, &status, WNOHANG | WUNTRACED)) > 0)
{
if (WIFSIGNALED(status) || WIFSTOPPED(status))
{
int jid = pid2jid(pid);
safe_print("Job [");
safe_print(jid);
safe_print("] (");
safe_print(pid);
safe_print(") ");
if (!WIFSTOPPED(status) && WTERMSIG(status) == SIGINT)
safe_print("terminated");
else if (WIFSTOPPED(status))
safe_print("stopped");
else
safe_print("idk");
safe_print(" by signal ");
if (WIFSTOPPED(status))
safe_print(WSTOPSIG(status));
else
safe_print(WTERMSIG(status));
safe_print("\n");
}
if (WIFSTOPPED(status))
{
safe_debug("suspended pid: ");
safe_debug(pid);
safe_debug("\n");
sigset_t prev_inner;
block_all(&prev_inner);
job_suspend(pid);
sigprocmask(SIG_SETMASK, &prev_inner, nullptr);
}
else {
safe_debug("terminated pid: ");
safe_debug(pid);
sigset_t prev_inner;
block_all(&prev_inner);
deletejob(pid);
sigprocmask(SIG_SETMASK, &prev_inner, nullptr);
}
}
sigprocmask(SIG_SETMASK, &prev, nullptr);
errno = errno_backup;
return;
}
/*
* sigint_handler - The kernel sends a SIGINT to the shell whenver the
* user types ctrl-c at the keyboard. Catch it and send it along
* to the foreground job.
*/
void sigint_handler([[maybe_unused]] int sig)
{
int errno_backup = errno;
sigset_t prev;
block_handler(&prev);
int pid = fgpid();
if (pid != 0)
{
kill(-pid, SIGINT);
} else {
char *buf = "\n";
tcflush(STDIN_FILENO, TCIFLUSH);
ioctl(STDIN_FILENO, TIOCSTI, buf);
}
sigprocmask(SIG_SETMASK, &prev, nullptr);
errno = errno_backup;
return;
}
/*
* sigtstp_handler - The kernel sends a SIGTSTP to the shell whenever
* the user types ctrl-z at the keyboard. Catch it and suspend the
* foreground job by sending it a SIGTSTP.
*/
void sigtstp_handler([[maybe_unused]] int sig)
{
int errno_backup = errno;
sigset_t prev;
block_handler(&prev);
int pid = fgpid();
if (pid != 0)
{
kill(-pid, SIGTSTP);
}
sigprocmask(SIG_SETMASK, &prev, nullptr);
errno = errno_backup;
return;
}
int block_all(sigset_t *prev)
{
sigset_t set;
sigfillset(&set);
return sigprocmask(SIG_SETMASK, &set, prev);
}
int block_handler(sigset_t *prev)
{
return sigprocmask(SIG_BLOCK, &block_job, prev);
}
void sigquit_handler([[maybe_unused]] int sig)
{
printf("Terminating after receipt of SIGQUIT signal\n");
exit(1);
}
}
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